1. Field of the Invention
This invention relates to machine elements and mechanisms generally, but more particularly to motor gear boxes.
2. Description of the Related Art
The present invention is an improvement upon the compact miniature motor gear box shown in U.S. Pat. No. 6,054,785 which was issued on Apr. 25, 2000, to Kerdjoudj et al. and in U.S. Des. Pat. No. D440,995 which was issued on Apr. 24, 2001, to Tsergas et al.
FIG. 1 shows a bottom plan view of a prior art motor gear box 100 with built-in mounting brackets 168 at each end. A separate sleeve 102 surrounds an output shaft (not shown) that protrudes from the gear box 100.
FIG. 2 shows a cross-sectional side elevational view of the prior art motor gear box 100 with the built-in mounting brackets 168 at each end and the separate sleeve 102 which surrounds the output shaft (not shown) that protrudes from the gear box 100.
FIG. 3 shows a cutaway top plan view taken along line 3—3 of FIG. 2 showing the prior art motor gear box 100 with the separate sleeve 102 and other sleeves 104, 106 and 108 interconnected by reinforcing ribs 103, 105 and 107, respectively. These other sleeves 104, 106 and 108 surround other gear shafts (not shown). Other reinforcing ribs 109, 111, 112 and 113 provide rigidity to a frame 114 which surrounds the sleeves and ribs mentioned above.
FIG. 4 shows another cutaway top plan view taken along line 4—4 of FIG. 2 showing the prior art motor gear box 100 with the frame 114 surrounding a direct current (DC) motor 110. A programmable control board (PCB) 122 is mounted on a rear end 130 of the DC motor 110 while a first-stage worm gear 132 protrudes from a front end 120 of the DC motor 110. This first-stage worm gear 132 meshes with a double pinion transfer gear 134.
FIG. 8 shows a bottom plan view of another prior art motor gear box 200 with built-in mounting tabs 268 at each corner. A separate sleeve 202 surrounds an output shaft (not shown) that protrudes from the gear box 200. A housing 214 contains the DC motor 10 of FIGS. 5 and 6 and includes in FIG. 8 a dome 250 which protects a second gear pin 50 (see FIG. 6) inside the gear box 200. Each mounting tab 268 has a through hole 204 which is partially surrounded by a curved wall 206 that serves to protect a screw or a bolt (not shown) which passes through the hole 204.